A HISTORY OF HERTFORDSHIRE TABLE VII MEAN RAINFALL IN EACH DISTRICT, WITH ITS RELATION TO COUNTY MEAN River District 1860-69 1870-79 1880-89 1890-99 inches per cent. inches per cent. inches per cent. inches per cent. Cam
- Rhee . . .
23-47 IO 23'55 -16 23.50 - 12 22-37 IO Ivel Hiz . . . . 23-89 -9 25-61 -8 25-27 -5 23-61 -5 Thame : Up. Thame
26-10
+ 5
r Bulbourne
29-2O
+ 12
31-00
+ ii
29-60
+ IO
25-94
+ 5
Gade . . .
26'29
+ I
28-59
+ 2
28-46
+ 6
25-87
+ 5
Colne{ Ver ...
27-45
+ 5
29-56
+ 6
28-44
+ 6
26-35
+ 6
1 Upper Colne .
24-64
=
v. Lower Colne .
27-63
i
30-98
+ 16
26-54
+ 7
' Mimram
25-58 -4 23-82 -4 Beane .
26-25
-6
24-61
/-,_ ,
Rib ....
25-04
-6
24-22
2
Lita
Ash ....
26-24
-6
25-98
-3
24-82
=
Upper Lea . .
25-OI
-4
27-10
-3
24-69
-8
23-11
-7
^ Lower Lea .
2 7 - 7 8 + 4 23-65 -5 During the last half-century there have been falls of rain of at least z inches in twenty-four hours on twelve occasions. On the lath of July, 1889, such a fall occurred at eighteen stations out of thirty then recording, and at least 3! inches at four of these. Falls of at least 3 inches have occurred on seven occasions, and of at least 3! inches on 30th June, 1878 ; I2th July, 1889, the day with the greatest average rainfall at all stations ; and iyth July, 1890, the day with the greatest fall of rain at any one station, viz. 4' 19 inches at Moor Park, Rick- mansworth. Two other elements of climate, viz., sunshine and wind, remain for consideration, but can only be very briefly noticed. The following are averages for the twelve years 1887-98 for wind at Berkhamsted, St. Albans, and Bennington, and for sunshine at Berkhamsted only. The prevailing direction of the wind is from S.W. (sixty-one days in the year) to W. (sixty-two days), and the next most frequent winds are N. to N.E. and S. (each about thirty-seven days). The least frequent are S.E. (twenty-five days). About forty-four days in the year are re- corded as calm. March is the most windy month, June the calmest. The duration of bright sunshine is least in December and greatest in May; December having rather more than an hour a day, and May nearly six and a half hours. Throughout the year the sun shines brightly for nearly four hours a day. 40
